Rotary channel-selector valve

ABSTRACT

A rotary channel-selector valve is provided, which includes: a valve-seat plate covering one end of a cylindrical valve housing and provided with low and high pressure ports and two switching ports all connecting the inside and the outside of the valve; and a main valve element accommodated in the valve housing and provided with low and high pressure connecting grooves on one end surface thereof, wherein one (or the other) of the switching ports communicates with the low pressure port through the low pressure connecting groove and simultaneously the other (or one) thereof communicates with the high pressure port through the high pressure connecting groove at a first (or second) channel-switching position of the main valve element. A bulkhead is provided on a bottom surface of the high pressure connecting groove and both end portions of the high pressure connecting groove open to an inner surface of the valve housing through respective high pressure fluid jetting grooves so as to hold stable the main valve element at the first or second channel-switching position. Flow of high pressure fluid jetting to the high pressure connecting groove is then disturbed by the bulkhead, difference in power between flow of the high pressure fluid jetting from the both end portions of the high pressure connecting groove to the periphery of the main valve element through the respective high pressure fluid jetting grooves arises and brings about rotating force to the main valve element, and thus the main valve element being it rotation can surely get to a due channel-switching position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a rotary channel-selectorvalve and more particularly, to a rotary channel-selector valve such asa 4-way valve which is applied to a switching mechanism ofheating/cooling in a heat pump system and to a structure of a main valveelement of the valve.

2. Description of the Related Art

A channel-selector valve wherein a main valve element separates from avalve-seat plate during valve-switching movement by opening or closing apilot passage penetrating the main valve element in an axial directionhas been proposed by the same applicant in Japanese Patent ApplicationLaid-open No.9-292050 (hereinafter "JP '050") as a rotarychannel-selector valve wherein a connecting point of a low pressure portprovided on a valve-seat plate, fixed to a valve housing and put intocontact with an end surface of a main valve element, shifts from one offirst and second switching ports on the valve-seat plate to the otherone thereof by rotating, in the valve housing, the main valve element,having a high pressure connecting groove and a low pressure connectinggroove on the end surface thereof, between first and secondchannel-switching positions and simultaneously a connecting point of ahigh pressure port of the valve-seat plate shifts from the other one ofthe first and second switching ports to the one thereof.

A 4-way valve proposed in JP '050 is superior to a conventional one inthe following points. That is, the 4-way valve in JP '050 enables a heatpump system to start cooling or operation in a shorter time aftervalve-switching movement since a high pressure port and a low pressureport communicates during the valve-switching movement thereby toequalize pressure in both of the pressure ports without stopping acompressor, differing from a conventional rotary channel-selector valve,and further the main valve element can be rotated with smaller forcesince static friction force at rotation start and also slidingresistance both between the main valve element and the valve-seat plateare smaller due to the separation of the main valve element from thevalve-seat plate during the valve-switching movement.

As described above, since the 4-way valve proposed in JP '050 executesthe valve switching movement without stopping the compressor, a space isformed between the valve-seat plate and the main valve element separatedfrom the valve-seat plate during the valve-switching movement, andtherefore the main valve element is pushed in a direction of separatingthe main valve element from the valve-seat plate by pressure of a highpressure fluid filled in the space.

Consequently, the main valve element separated from the valve-seat plateshould abut against any member in the valve housing and movement of theseparation of the main valve element from the valve-seat plate should belimited and the main valve element should be pushed on the member.

Therefore, if the fluid pressure in the space formed between thevalve-seat plate and the main valve element separated from thevalve-seat plate is too high, the main valve element beginning rotationbetween the first channel-switching position and the secondchannel-switching position is forced to stop on the way by contactresistance against the above member limiting the separation movement,thereby causing incomplete rotation of the main valve element.

Moreover, since the high pressure fluid jetting from the high pressureport to the space between the main valve element and the valve-seatplate during the valve-switching movement is not simply directed to thelow pressure port and turbulent flow arises by an existence of the highand low pressure connecting grooves formed on the end surface of themain valve element, the main valve element beginning rotation betweenthe first and second channel-switching positions is forced to stop onthe way by receiving rotating force opposite to the rotating direction,thereby causing incomplete rotation of the main valve element.

More specifically, the 4-way valve proposed in JP '050 has a structureconsisting of the valve housing being in a cylindrical shape; the mainvalve element provided in the valve housing rotatably and axiallymovably; the valve-seat plate fixed to the valve housing and having thelow pressure port connected to a low pressure piping, the high pressureport connected to a high pressure piping, and at least one switchingport; a pilot valve supported by the main valve element by axiallymovably engaging a valve holding hole formed in the main valve elementfor selectively connecting the low pressure port to a pressure chamberformed on one end surface side of the main valve element and receivingpressure of the high pressure port by opening or closing a valve portformed on the main valve element; and an electromagnetic solenoid forrotating the main valve element and for opening or closing the pilotvalve, wherein the end surface, facing oppositely to the pressurechamber, of the main valve element is put into contact with thevalve-seat plate and the main valve element selectively connects theswitching port to either one of the low pressure port and the highpressure port by rotation of the main valve element itself.

With respect to the above conventional rotary channel-selector valve ofJP '050, since the pilot valve consists integrally of the stem portionengaging the valve holding hole axially movably and attracted by theelectromagnetic solenoid and of a needle valve portion to open or closethe valve port, a supporting condition of the stem portion by the valveport directly affects radial position or directional position of theneedle valve portion relative to the valve port, thereby causing auncertainty of shutting off the valve port by the needle valve portion.

Especially, in case of providing a communicating passage connecting thevalve port and the pressure chamber between the stem portion of thepilot valve and the valve holding hole to receive the stem portion, thestem portion would get rickety, whereby radial position or directionalposition of the needle valve portion relative to the valve port becomesunstable, thereby making shutoff characteristics of the valve port bythe needle valve portion worse.

Further, a concentric machining accuracy between the stem portion andthe needle valve portion and also a concentric machining accuracybetween the valve holding hole and the valve port also affect shutoffcharacteristics of the valve port, and accordingly designed shutoffcharacteristics of the valve port can not be attained without the abovemachining accuracy being high.

In case that the stem portion of the pilot valve is held by both of thevalve housing and the main valve element by means of engagement of thestem portion with a pilot valve guide-tube formed on the valve housinghaving the electromagnetic solenoid and with the valve holding hole ofthe main valve element having the valve port, a positioning accuracy ofthe pilot valve guide-tube formed on the valve housing and an assemblingaccuracy of the main valve element to the valve housing directly affectsradial position or directional position of the needle valve portionrelative to the valve port, thereby causing a uncertainty of shuttingoff the valve port by the needle valve portion.

And, in case that a fixed attractor of the electromagnetic solenoid isprovided on the pilot valve guide-tube of the valve housing oppositelyto one end of the stem portion of the pilot valve and also a chamber isformed in the pilot valve guide-tube and between the stem portion andthe fixed attractor, fluid like a lubricant or a refrigerant wouldinvade the chamber through clearance between the stem portion and thepilot valve guide-tube and stay in the chamber, thereby causing auncertainty of smooth opening and closing movement of the pilot valve.

Further, with respect to the above rotary channel-selector valve, theelectromagnetic coil is fixed to the magnetic pole equippingelectromagnetic surface of the valve housing for rotating the main valveelement by the magnetic action against a multipolar magnet.

In the above rotary channel-selector valve and the like, since themagnet pole pieces, magnetized by the electromagnetic coil, on the valvehousing side rotates the main valve element by the magnetic actionagainst the multipolar magnet on the main valve element side, the magnetpole pieces have to be circumferentially positioned on the valve housingfor rotating the main valve element accurately between a predeterminedchannel-switching positions. To cope with the above, for example, a4-way valve disclosed in Japanese Patent Application Laid-openNo.8-42737 (hereinafter "JP '737") has a positioning projection providedon a body-cap of a body (a valve housing) and simultaneously a concaveformed on one end surface, contacting the above body-cap, of a coilbobbin of an electromagnet having an iron core (magnet pole pieces), andthen the magnet pole pieces are circumferentially positioned on thevalve housing by positioning the electromagnet relatively to the valvehousing by means of engagement between the positioning projection on thebody-cap and the concave of the coil bobbin.

The above positioning means of the magnet pole pieces of the 4-way valvefunctions satisfactorily. However, the positioning means would requirean improvement for necessity of forming a concave or convex on the coilbobbin, wherein troublesome work of designing a metal moldcorrespondingly to the concave or convex is required, in comparison withforming a concave or convex on a body side by method of punching orpressing, since the positioning between the body and the coil bobbin isdone by direct engagement between them.

SUMMARY OF THE INVENTION

In view of the foregoing, an first object of the present invention is toprovide a rotary channel-selector valve wherein rotary switchingmovement of a main valve element can be surely performed withoutincreasing rotating force given from outside even in case that therotary switching movement is executed in a state of the main valveelement being separated from a valve-seat plate.

And, a second object of the present invention is to provide a rotarychannel-selector valve wherein even if a supporting condition of a stemportion by a valve port, a concentricity between the stem portion and aneedle valve portion, a concentric machining accuracy between a valveholding hole and the valve port, a positioning accuracy of a pilot valveguide-tube, or an assembling accuracy of a main valve element to a valvehousing is not so good, radial position or directional position of theneedle valve portion relative to the valve port can be corrected, thevalve port is surely shut off by the needle valve portion, and a shockto the valve port and to the needle valve portion at the time of closingthe pilot valve can be lightened.

Further, a third object of the present invention is to provide a rotarychannel-selector valve wherein even if fluid like a lubricant or arefrigerant invades a chamber formed with a pilot valve guide-tube, astem portion, and a fixed attractor, the fluid does not stay in thechamber so that smooth opening and closing movement of the pilot valvecan be assured for a long period.

Still further, a fourth object of the present invention is to provide arotary channel-selector valve wherein circumferential positioning ofmagnet pole pieces can be surely performed without newly forming astructure on a coil bobbin itself for the positioning.

In order to achieve the above-described first object, as a first aspectof the present invention, a rotary channel-selector valve consists of: avalve housing; a main valve element accommodated in the valve housing,being capable of rotating between a first channel-switching position anda second channel-switching position, and having high and low pressureconnecting grooves isolated from each other on one end surface thereof;a valve-seat plate, fixed to the valve housing, facing the one endsurface of the main valve element, and having high and low pressureports and first and second switching ports, wherein a connecting pointof the high pressure port shifts from one of the first and secondswitching ports to the other thereof through the high pressureconnecting groove by rotating the main valve element between the firstand second channel-switching positions and simultaneously a connectingpoint of the low pressure port shifts from the other of the first andsecond switching ports to the one thereof through the low pressureconnecting groove, and rotation of the main valve element between thefirst and second channel-switching positions is performed with the oneend surface of the main valve element being apart from the valve-seatplate; a first high pressure fluid jetting groove formed on the one endsurface of the main valve element, wherein one end portion, of the highpressure connecting groove, positioned near the high pressure port atthe first channel-switching position opens to a periphery of the mainvalve element through the first high pressure fluid jetting groove; asecond high pressure fluid jetting groove formed on the one end surfaceof the main valve element and being isolated from the first highpressure fluid jetting groove, wherein another end portion, of the highpressure connecting groove, positioned near the high pressure port atthe second channel-switching position opens to the periphery of the mainvalve element through the second high pressure fluid jetting groove; anda bulkhead being in a shape of a projecting strip and provided on abottom surface of the high pressure connecting groove, wherein sincehigh pressure fluid jetting from the high pressure port to the highpressure connecting groove flows easier toward the first high pressurefluid jetting groove than toward the second high pressure fluid jettinggroove by an action of the bulkhead in a state that the high pressureport positions nearer one end portion of the high pressure connectinggroove than the bulkhead, power of a first high pressure flow jettingfrom the first high pressure fluid jetting groove to the periphery ofthe main valve element wins power of a second high pressure flow jettingfrom the second high pressure fluid jetting groove to the periphery ofthe main valve element and rotating force in a direction from the secondchannel-switching position to the first channel-switching position actson the main valve element due to difference of power between the firsthigh pressure flow and the second high pressure flow, and, on thecontrary, since high pressure fluid jetting from the high pressure portto the high pressure connecting groove flows easier toward the secondhigh pressure fluid jetting groove than toward the first high pressurefluid jetting groove by an action of the bulkhead in a state that thehigh pressure port positions nearer another end portion of the highpressure connecting groove than the bulkhead, power of a second highpressure flow jetting from the second high pressure fluid jetting grooveto the periphery of the main valve element wins power of a first highpressure flow jetting from the first high pressure fluid jetting grooveto the periphery of the main valve element and rotating force in adirection from the first channel-switching position to the secondchannel-switching position acts on the main valve element due todifference of power between the first high pressure flow and the secondhigh pressure flow.

In order to achieve the above-described second object, as a secondaspect of the present invention, a rotary channel-selector valveconsists of: a valve housing being in a cylindrical shape; a main valveelement provided in the valve housing rotatably and axially movably; avalve-seat plate fixed to the valve housing and having a low pressureport connected to a low pressure piping, a high pressure port connectedto a high pressure piping, and at least one switching port; a pilotvalve supported by the main valve element by axially movably engaging avalve holding hole formed in the main valve element for selectivelyconnecting the low pressure port to a pressure chamber formed on one endsurface side of the main valve element and suffering pressure of thehigh pressure port by opening or closing a valve port formed on the mainvalve element; and an electromagnetic solenoid for rotating the mainvalve element and for opening or closing the pilot valve, wherein an endsurface, facing oppositely to the pressure chamber, of the main valveelement is put into contact with the valve-seat plate and the main valveelement selectively connects the switching port to either one of the lowpressure port and the high pressure port by rotation of the main valveelement itself, and the pilot valve consists separately of a stemportion engaging the valve holding hole axially movably and attracted bythe electromagnetic solenoid and of a needle valve portion to open orclose the valve port so as to enable the needle valve portion to shiftradially and axially with respect to the stem portion.

In order to achieve the above-described third object, as a third aspectof the present invention, a rotary channel-selector valve consists of: avalve housing being in a cylindrical shape; a main valve elementprovided in the valve housing rotatably and axially movably; avalve-seat plate fixed to the valve housing and having a low pressureport connected to a low pressure piping, a high pressure port connectedto a high pressure piping, and at least one switching port; a pilotvalve supported by the main valve element by axially movably engaging avalve holding hole formed in the main valve element for selectivelyconnecting the low pressure port to a pressure chamber formed on one endsurface side of the main valve element and suffering pressure of thehigh pressure port by opening or closing a valve port formed on the mainvalve element; an electromagnetic solenoid for rotating the main valveelement and for opening or closing the pilot valve, wherein an endsurface, facing oppositely to the pressure chamber, of the main valveelement is put into contact with the valve-seat plate and the main valveelement selectively connects the switching port to either one of the lowpressure port and the high pressure port by rotation of the main valveelement itself; a pilot valve guide-tube constituting the valve housingfor receiving a stem portion of the pilot valve axially movably; a fixedattractor, of the electromagnetic solenoid, provided on the pilot valveguide-tube oppositely to one end of the stem portion; and a bleedingpassage formed in the stem portion for opening a chamber, formed in thepilot valve guide-tube and between the stem portion and the fixedattractor, to the pressure chamber.

In order to achieve the above-described fourth object, as a fourthaspect of the present invention, a rotary channel-selector valveconsists of: a valve housing being in a cylindrical shape and having avalve-seat portion therein; a main valve element provided in the valvehousing rotatably within a predetermined range of angle forchannel-switching along with the valve-seat portion by rotation; amultipolar magnet fixed to the main valve element; an electromagneticcoil; and a magnetic pole equipping electromagnetic coil attaching bodyfixed to the valve housing, equipped with the electromagnetic coil, andhaving magnet pole pieces magnetized by the electromagnetic coil andfacing a peripheral surface of the valve housing for rotating the mainvalve element by a magnetic action against the multipolar magnet,wherein the valve housing has a flat surface partially on the peripheralsurface thereof and the magnetic pole equipping electromagnetic coilattaching body has a whirl-stopping piece surface-engaging the flatsurface so that the magnetic pole equipping electromagnetic coilattaching body is circumferentially positioned on the valve housing by asurface-engagement between the flat surface and the whirl-stoppingpiece.

In order to achieve the above-described fourth object, further as afifth aspect of the present invention, a rotary channel-selector valvemay consist of: a valve housing being in a cylindrical shape and havinga valve-seat portion therein; a main valve element provided in the valvehousing rotatably within a predetermined range of angle forchannel-switching along with the valve-seat portion by rotation; amultipolar magnet fixed to the main valve element; an electromagneticcoil; and a magnetic pole equipping electromagnetic coil attaching bodyfixed to the valve housing, equipped with the electromagnetic coil, andhaving magnet pole pieces magnetized by the electromagnetic coil andfacing a peripheral surface of the valve housing for rotating the mainvalve element by a magnetic action against the multipolar magnet,wherein the valve housing has a mounting engagement portion with a flatside-surface and the magnetic pole equipping electromagnetic coilattaching body has a concave to engage the mounting engagement portionso that the magnetic pole equipping electromagnetic coil attaching bodyis circumferentially positioned on the valve housing by engaging themounting engagement portion with the concave.

According to the first aspect of the rotary channel-selector valve inaccordance with the present invention, the main valve element rotatesfrom the first channel-switching position to the secondchannel-switching position, and with a shift of position of the highpressure port from a state that the high pressure port is relativelypositioned nearer one end portion of the high pressure connecting groovethan the bulkhead to another state that the high pressure port isrelatively positioned nearer the other end portion of the high pressureconnecting groove than the bulkhead, power of the first high pressureflow jetting from the high pressure port to the high pressure connectinggroove and then from the first high pressure fluid jetting groove to theperiphery of the main valve element wins power of the second highpressure flow jetting from the high pressure port to the high pressureconnecting groove and then from the second high pressure fluid jettinggroove to the periphery of the main valve element, and accordingly,rotating force to the main valve element in a direction from the firstchannel-switching position to the second channel-switching positionarises.

On the other hand, the main valve element rotates from the secondchannel-switching position to the first channel-switching position, andwith a shift of position of the high pressure port from a state that thehigh pressure port is relatively positioned nearer the other end portionof the high pressure connecting groove than the bulkhead to anotherstate that the high pressure port is relatively positioned nearer oneend portion of the high pressure connecting groove than the bulkhead,power of the second high pressure flow jetting from the high pressureport to the high pressure connecting groove and then from the secondhigh pressure fluid jetting groove to the periphery of the main valveelement wins power of the first high pressure flow jetting from the highpressure port to the high pressure connecting groove and then from thefirst high pressure fluid jetting groove to the periphery of the mainvalve element, and accordingly, rotating force to the main valve elementin a direction from the second channel-switching position to the firstchannel-switching position arises.

In other words, even if the main valve element starts rotation from anyone of the first and second channel-switching positions to the otherchannel-switching position, additional rotating force having the samedirection as the other force from the outside and caused by differenceof power between the first high pressure flow and the second highpressure flow newly acts on the main valve element simultaneously withshift of relative position of the high pressure port to an opposite endof the high pressure connecting groove by passing the bulkhead.

Accordingly, in a state of the main valve element being apart from thevalve-seat plate during rotation of the main valve element between thefirst channel-switching position and the second channel-switchingposition, even if force arises due to fluid pressure in a space formedbetween the main valve element and the valve-seat plate and separatesthe main valve element from the valve-seat plate, or even if rotatingforce, being in an opposite direction to the rotating direction, due toa turbulent flow arising in a space formed between the main valveelement and the valve-seat plate acts on the main valve element, themain valve element can be surely rotated to the final rotating position,thereby completing valve switching movement.

Also, according to the rotary channel-selector valve in accordance withthe present invention, a valve outside-passage communicating with thehigh pressure port is formed between an inner surface of the valvehousing and a periphery of the main valve element, a pressure chambercommunicating with the valve outside-passage is formed between one endsurface of the main valve element and the valve housing, a gate portionopening the high pressure connecting groove to the periphery of the mainvalve element is formed on the other end surface of the main valveelement, and a pilot passage connecting the low pressure connectinggroove and the pressure chamber and being capable of flowing largerquantity than that of the valve outside-passage is formed in the mainvalve element. The main valve element is pushed to the valve-seat plateside by the high pressure fluid flowing into the pressure chamberthrough the gate portion and the valve outside-passage after jettingfrom the high pressure port to the high pressure connecting groove byclosing the pilot passage provided in the valve housing by the pilotvalve, and, on the contrary, the main valve element separates from thevalve-seat plate by disappearance of force pushing the main valveelement toward the valve-seat plate by drop of pressure in the pressurechamber by opening the pilot passage by the pilot valve. The first highpressure fluid jetting groove and the second high pressure fluid jettinggroove each have a larger cross-section than that of the gate portion.And, power of the first high pressure flow wins that of a third highpressure flow jetting from the high pressure connecting groove to theperiphery of the main valve element through the gate portion in a statethat the high pressure port positions nearer one end portion of the highpressure connecting groove than the bulkhead, and, on the contrary,power of the second high pressure flow wins that of the third highpressure flow jetting from the high pressure connecting groove to theperiphery of the main valve element through the gate portion in a statethat the high pressure port positions nearer another end portion of thehigh pressure connecting groove than the bulkhead, thereby enabling thefollowings.

In other words, one end surface of the main valve element abuts on thevalve-seat plate by introducing the high pressure fluid, jetting fromthe high pressure port to the high pressure connecting groove of themain valve element, to the pressure chamber through the gate portion ofthe main valve element and the valve outside-passage and, on thecontrary, the one end surface of the main valve element separates fromthe valve-seat plate by introducing the high pressure fluid of thepressure chamber into the low pressure port through the pilot passage ofthe main valve element with the pilot valve being in a opened state andthrough the low pressure connecting groove. This structure can preventan additional rotating force, newly acting on the main valve element bydifference of power between the first high pressure flow and the secondhigh pressure flow and having the same direction as another force givenfrom the outside, from being weakened or vanished.

And, the above-mentioned main valve element with the gates and the highpressure fluid jetting grooves has a structural feature of eventhickness being advantageous for the molding process, which enablesimprovement of dimensional accuracy and manufacturing stability, therebyimproving a yield rate and reducing a cost.

Further, pressure loss can be reduced, or a flow coefficient can beincreased by studying rotation property of the main valve element andfurther studying shape of the main valve element for attaining betterstability in channel-switching movement.

According to the second aspect of the rotary channel-selector valve inaccordance with the present invention, since a needle valve portion isseparately formed from a stem portion of a pilot valve so as to enablethe needle valve portion to shift radially and axially in the stemportion, the needle valve portion tilts relatively to the valve portcorrespondingly to difference in radial or axial position between theneedle valve portion and the valve port, that is, with thisself-aligning structure, position of the needle valve portion relativeto the valve port can be corrected, and even if a supporting conditionof the stem portion by the valve port, a concentricity between the stemportion and the needle valve portion, a concentric machining accuracybetween a valve holding hole and the valve port, a positioning accuracyof a pilot valve guide-tube, or an assembling accuracy of the main valveelement to a valve housing is not so good, radial position ordirectional position of the needle valve portion relative to the valveport can be corrected, thereby ensuring to shut off the valve port withthe needle valve portion.

Further, since the needle valve portion and the stem portion areconnected movably in the axial direction of the main valve element, ashock of a hit by the needle valve portion against the valve port at thetime of closing the pilot valve can be lightened, thereby improvingdurability of the needle valve portion and the valve port against wearor chipping or the like.

And, according to the rotary channel-selector valve in accordance withthe present invention, since a spherical portion of the needle valveportion abuts on the stem portion, the needle valve portion can tiltself-aligningly against the stem portion and directional position of theneedle valve portion relative to the stem portion can be corrected, andconsequently, even if a supporting condition of the stem portion by thevalve port, a concentricity between the stem portion and the needlevalve portion, a concentric machining accuracy between the valve holdinghole and the valve port, a positioning accuracy of the pilot valveguide-tube, or an assembling accuracy of the main valve element to thevalve housing is not so good, directional position of the needle valveportion relative to the valve port can be corrected, thereby ensuring toshut off the valve port with the needle valve portion.

Also, since a high-slippery resin plate is provided at an abuttingportion between the spherical portion and the stem portion, the needlevalve portion can surely tilt self-aligningly with low resistance, anddirectional position of the needle valve portion relative to the valveport can be corrected, thereby ensuring to shut off the valve port withthe needle valve portion.

Further, according to the rotary channel-selector valve in accordancewith the present invention, since a compression spring is assembledbetween the needle valve portion and the stem portion, the needle valveportion does not get rickety against the stem portion in a valve-openedstate and valve closing-pressure can be controlled with the compressioncoil spring.

Also, since a shock of a hit by the needle valve portion against thevalve port at the time of closing the pilot valve can be absorbed by thecompression spring, shock reducing effect increases and then durabilityof the needle valve portion and the valve port against wear or chippingor the like can be improved.

Still further, according to the rotary channel-selector valve inaccordance with the present invention, since a chamber formed with apilot valve guide-tube, the stem portion, and a fixed attractor opens toa pressure chamber through a bleeding passage, fluid like a lubricant ora refrigerant does not stay in the chamber, thereby assuring smoothopening and closing movement of the pilot valve for a long period.

Finally, according to the rotary channel-selector valve in accordancewith the present invention, the valve-seat plate has two switching portsof first and second switching ports, and the main valve element canrotate between a first channel-switching position, which connects a lowpressure port to the first switching port and simultaneously a highpressure port to the second switching port, and a secondchannel-switching position, which connects the low pressure port to thesecond switching port and simultaneously the high pressure port to thefirst switching port, thus enabling the followings as a 4-way valve usedin the heat pump system.

Namely, by the rotation of the main valve element between a firstchannel-switching position, which connects a low pressure port to thefirst switching port and simultaneously a high pressure port to thesecond switching port, and a second channel-switching position, whichconnects the low pressure port to the second switching port andsimultaneously the high pressure port to the first switching port, therotary channel-selector valve functions as a 4-way valve used in theheat pump system, thereby ensuring to shut off the valve port with theneedle valve portion and assuring smooth opening and closing movement ofthe pilot valve for a long period.

According to the third aspect of the rotary channel-selector valve inaccordance with the present invention, since a magnetic pole equippingelectromagnetic coil attaching body is circumferentially positioned on avalve housing wherein a rotatable range of a main valve element islimited within a predetermined angle by a surface-engagement between aflat surface formed on a peripheral surface of the valve housing and awhirl-stopping piece of the magnetic pole equipping electromagnetic coilattaching body, circumferential positioning of magnet pole pieces can besurely performed without newly forming a structure on a coil bobbinitself of an electromagnetic coil for the positioning.

And, according to the rotary channel-selector valve in accordance withthe present invention, the magnetic pole equipping electromagnetic coilattaching body has an outer box, having a pair of main magnetic polepieces arranged with a circumferential difference by 180 degrees eachother, and an under plate, made of a metal sheet and having a pair ofminor magnetic pole pieces assembled to the outer box with acircumferential difference by 180 degrees each other and also with acircumferential difference by 90 degrees against the main magnetic polepieces and further the whirl-stopping piece is formed by downwardlybending the under plate, which enables the followings.

Namely, since the magnetic pole equipping electromagnetic coil attachingbody consists of the outer box having main magnetic pole pieces and theunder plate made of a metal sheet and having minor magnetic pole piecesand the magnetic pole equipping electromagnetic coil attaching body iscircumferentially positioned on the valve housing by thesurface-engagement between the flat surface formed on the peripheralsurface of the valve housing and the whirl-stopping piece of the underplate, circumferential positioning of the magnet pole pieces can besurely performed without newly forming a structure on the coil bobbinitself of the electromagnetic coil for the positioning.

According to fourth and fifth aspects of the rotary channel-selectorvalve in accordance with the present invention, since a magnetic poleequipping electromagnetic coil attaching body is circumferentiallypositioned on a valve housing wherein a rotatable range of a main valveelement is limited within a predetermined angle by engaging a mountingengagement portion formed on an fixed attractor and having flatside-surfaces with a concave of a magnetic pole equippingelectromagnetic coil attaching body, circumferential positioning of mainand minor magnetic pole pieces can be surely performed without newlyforming a structure on the coil bobbin itself of the electromagneticcoil for the positioning.

And, according to the rotary channel-selector valve in accordance withthe present invention, since the magnetic pole equipping electromagneticcoil attaching body has an outer box, having a pair of main magneticpole pieces arranged with a circumferential difference by 180 degreeseach other, and an under plate, made of a metal sheet and having a pairof minor magnetic pole pieces assembled to the outer box with acircumferential difference by 180 degrees each other and also with acircumferential difference by 90 degrees against the main magnetic polepieces and further the concave is press-formed on the outer box, therebyenabling the followings.

Namely, since the magnetic pole equipping electromagnetic coil attachingbody consists of the outer box having main magnetic pole pieces and theunder plate made of a metal sheet and having minor magnetic pole piecesand the magnetic pole equipping electromagnetic coil attaching body iscircumferentially positioned on the valve housing by engaging themounting engagement portion with the concave being press-formed on theouter box, circumferential positioning of the main and minor magneticpole pieces can be surely performed without newly forming a structure onthe coil bobbin itself of the electromagnetic coil for the positioning.

The above and other objects and features of the present invention willbecome more apparent from the following description taken in conjunctionwith the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a longitudinal sectional view showing a first embodiment of arotary channel-selector valve in accordance with the present invention;

FIG. 2 is a plan view showing the rotary channel-selector valve of FIG.1;

FIG. 3 is a bottom view showing the rotary channel-selector valve ofFIG. 1;

FIG. 4 is a side view showing the rotary channel-selector valve of FIG.1;

FIG. 5 is a flow diagram of refrigerant at a cooling operation of a heatpump system using the rotary channel-selector valve of FIG. 1;

FIG. 6 is a flow diagram of refrigerant at a heating operation of a heatpump system using the rotary channel-selector valve of FIG. 1;

FIG. 7 is a side view showing a main valve element of FIG. 1;

FIGS. 8A to 8D are end views of a variety of a pilot valve of FIG. 1;

FIG. 8E is a sectional view of the pilot valve of FIG. 8D;

FIG. 9 is a longitudinal sectional view showing a second embodiment of arotary channel-selector valve in accordance with the present invention;

FIG. 10 is a sectional view of a pilot valve of FIG. 9;

FIG. 11 is a sectional view showing a modified embodiment of a pilotvalve applicable to the rotary channel-selector valve of FIG. 9;

FIG. 12 is a sectional view showing other modified embodiment of a pilotvalve applicable to the rotary channel-selector valve of FIG. 9;

FIG. 13 is a sectional view showing other modified embodiment of a pilotvalve applicable to the rotary channel-selector valve of FIG. 9;

FIG. 14A is a sectional view showing other modified embodiment of apilot valve applicable to the rotary channel-selector valve of FIG. 9;

FIG. 14B is a plan view a leaf spring of FIG. 14A;

FIG. 15 is a longitudinal sectional view showing a third embodiment of arotary channel-selector valve in accordance with the present invention;

FIG. 16 is a plan view showing the rotary channel-selector valve of FIG.15;

FIG. 17 is a bottom view showing the rotary channel-selector valve ofFIG. 15;

FIG. 18 is a front view showing the rotary channel-selector valve ofFIG. 15;

FIG. 19 is a side view showing the rotary channel-selector valve of FIG.15;

FIG. 20 is a side view showing an assembled body made up of a valvehousing and a fixed attractor of the rotary channel-selector valve ofFIG. 15;

FIG. 21 is a plan view showing an assembled body made up of a valvehousing and a fixed attractor of the rotary channel-selector valve ofFIG. 15;

FIG. 22 is a front view showing an assembled body made up of a valvehousing, a fixed attractor, and an under plate of the rotarychannel-selector valve of FIG. 15;

FIG. 23 is a side view showing an assembled body made up of a valvehousing, a fixed attractor, and an under plate of the rotarychannel-selector valve of FIG. 15;

FIG. 24 is a plan view showing an assembled body made up of a valvehousing, a fixed attractor, and an under plate of the rotarychannel-selector valve of FIG. 15;

FIGS. 25A and 25B are sectional views each showing an electromagneticactuator portion of the rotary channel-selector valve of FIG. 15;

FIG. 26 is a front view, partly in section, showing a fourth embodimentof a rotary channel-selector valve in accordance with the presentinvention;

FIG. 27 is a plan view showing the rotary channel-selector valve of FIG.26;

FIG. 28 is a side view, partly in section, showing the rotarychannel-selector valve of FIG. 26;

FIG. 29 is a front view showing an assembled body made up of a valvehousing and a fixed attractor of the rotary channel-selector valve ofFIG. 26;

FIG. 30 is a plan view showing an assembled body made up of a valvehousing and a fixed attractor of the rotary channel-selector valve ofFIG. 26;

FIG. 31 is a side view showing an assembled body made up of a valvehousing and a fixed attractor of the rotary channel-selector valve ofFIG. 26;

FIG. 32 is a front view showing an assembled body made up of a valvehousing and a fixed attractor of a fifth embodiment of a rotarychannel-selector valve in accordance with the present invention;

FIG. 33 is a side view showing an assembled body made up of a valvehousing, a fixed attractor, and an outer box of the rotarychannel-selector valve of FIG. 32; and

FIG. 34 is a perspective view showing a mounting state between apositioning plate and a fixed attractor of the rotary channel-selectorvalve of FIG. 32.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described in furtherdetail with reference to the accompanying drawing figures. "specificstructure of a first embodiment of a rotary channel-selector valve inaccordance with the present invention"

FIGS. 1 to 8 show a structure of a first embodiment of a 4-way valve,used as a channel-selector valve in a refrigerating cycle, in accordancewith the present invention.

As shown in FIG. 1, the rotary channel-selector valve has a cylindricalvalve housing 1, a main valve element 3 provided rotatably and axiallymovably in the valve housing 1, a valve-seat plate 5 fixed to a bottomportion of the valve housing 1, a pilot valve 9 assembled to the mainvalve element 3, and an electromagnetic solenoid 11 installed on top ofthe valve housing 1.

As shown in FIG. 5, the rotary channel-selector valve is constructed asa 4-way valve 100 used in a heat pump system, and the valve-seat plate 5is provided, around its center, with a low pressure port 15 to beconnected to a low pressure piping 13 connected to an inlet of acompressor P in the heat pump system, a high pressure port 19 to beconnected to a high pressure piping 17 connected to an outlet of thecompressor P, a first switching port 23 to be connected to a piping 21connected to an indoor heat exchanger E, and a second switching port 27to be connected to a piping 25 connected to an outdoor heat exchanger C.

The valve housing 1 consists, as shown in FIG. 1, of a large-diametercylindrical portion 2 to receive the main valve element 3, a main valveelement guide-tube 6, and a pilot valve guide-tube 39 by integrallyconcentrically forming them with a pressing deep drawing process.

The valve housing 1 can be of a structure in which the large-diametercylindrical portion 2, the main valve element guide-tube 6, and thepilot valve guide-tube 39 are separately formed and assembled.

A central guide hole 29 provided on the bottom portion of the main valveelement 3 engages a center pin 31 fixed to the valve-seat plate 5, and atonguepiece-like guide portion 4 upwardly projecting from the main valveelement 3 engages the main valve element guide-tube 6 of the valvehousing 1 axially movably, whereby the main valve element 3 is capableof rotating around own axis between a first channel-switching positionand a second channel-switching position and of axially linearly movingup and down between a risen position and a dropped position.

The guide portion 4 is formed in opposition to a side of a high pressureconnecting groove 37 and prevents inclination of the main valve element3, caused by fluid pressure on a high pressure side, by means of anabutment on the main valve element guide-tube 6.

A bottom surface (one end surface) 33 of the main valve element 3 is putinto contact with the valve-seat plate 5 when the main valve element 3is at the dropped position, and as shown in FIGS. 4 and 5 the main valveelement 3 is provided with a low pressure connecting groove 35 and thehigh pressure connecting groove 37 which are apart from the center ofthe bottom surface 33 and are independent and isolated each other. Thelow pressure connecting groove 35 connects the low pressure port 15 tothe first switching port 23 or to the second switching port 27, and thehigh pressure connecting groove 37 connects the high pressure port 19 tothe first switching port 23 or to the second switching port 27.

More specifically, as shown in FIG. 5, when the main valve element 3 isat the first channel-switching position, the high pressure port 19 islocated near a portion of one end 37a of the high pressure connectinggroove 37, and the low pressure connecting groove 35 connects the lowpressure port 15 and the first switching port 23 and the high pressureconnecting groove 37 connects the high pressure port 19 and the secondswitching port 27.

On the other hand, as shown in FIG. 6, when the main valve element 3 isat the second channel-switching position, the high pressure port 19 islocated near a portion of the other end 37b of the high pressureconnecting groove 37, and the low pressure connecting groove 35 connectsthe low pressure port 15 and the second switching port 27 and the highpressure connecting groove 37 connects the high pressure port 19 and thefirst switching port 23.

Based on the above, in a switched state of the first channel-switchingposition of the main valve element 3, as shown in FIG. 5, a refrigerantcirculation of "compressor P→4-way valve 100→outdoor heat exchangerC→throttling D→indoor heat exchanger E→4-way valve 100→compressor P" isestablished and the heat pump system is set to a cooling mode.

On the other hand, in a switched state of the second channel-switchingposition of the main valve element 3, as shown in FIG. 6, anotherrefrigerant circulation of "compressor P→4-way valve 100→indoor heatexchanger E→throttling D→outdoor heat exchanger C→4-way valve100→compressor P" is established and the heat pump system is set to aheating mode.

As shown in FIG. 1, an end of the high pressure piping 17 projects intothe high pressure connecting groove 37 through the high pressure port19, the end of the high pressure piping 17 functions as a stopper 18which abuts on an inner wall surface of the high pressure connectinggroove 37 and limits rotation range of the main valve element 3 to areciprocating range between the first channel-switching position and thesecond channel-switching position.

As shown in FIGS. 5 and 6, the main valve element 3 is provided with abulkhead (a stabilizer) 38 by a projecting strip on a bottom surface (aceiling surface) intermediate the high pressure connecting groove 37,and the bulkhead 38 is positioned between the high pressure port 19 andthe second switching port 27 at the first channel-switching position andalso positioned between the high pressure port 19 and the firstswitching port 23 at the second channel-switching position.

As shown in FIGS. 5 and 7, near the respective end portions 37a,37b ofthe high pressure connecting groove 37, the main valve element 3 isprovided with first and second gates 40a,40b which open the vicinity ofeach of the end portions 37a,37b of the high pressure connecting groove37 to an inner surface of the valve housing 1.

Height of the bulkhead 38 shall be smaller than depth of the highpressure connecting groove 37 and shall not interfere with the end ofthe high pressure piping 17 projecting into the high pressure connectinggroove 37 as the stopper 18, that is, the height would be within a rangeof 1 to 3 mm with 1 to 3 mm in width. The gates 40a,40b shall not reachthe bottom surface (the ceiling surface) of the high pressure connectinggroove 37, in other words, depth of the gates 40a,40b shall be smallerthan thickness of the high pressure connecting groove 37, that is, wouldbe within a range of 3 to 7 mm.

A skirt portion 42 to slide on the inner surface of the valve housing 1is provided between the both gates 40a,40b. Extend angle α of the skirtportion 42 would be between 40˜100 degrees.

The main valve element 3 is provided, on the bottom surface 33 thereof,with first and second high pressure fluid jetting grooves 44a,44barranged on respective sides of the low pressure connecting groove 35and connecting the respective end portions 37a,37b of the high pressureconnecting groove 37 to the periphery of the main valve element 3. Depthand width of both the high pressure fluid jetting grooves 44a,44b wouldbe between 10 to 15 mm, and 1 to 7 mm, respectively, and separationangle β of both the high pressure fluid jetting grooves 44a,44b would bebetween 60 to 180 degrees.

Whole of the main valve element 3 is made of molded plastic, and theports 15,19,23, and 27, the low pressure connecting groove 35, the highpressure connecting groove 37, the bulkhead 38, the first and secondgates 40a,40b, the skirt portion 42, and the first and second highpressure fluid jetting grooves 44a,44b all are integrally formed.

And, a multipolar magnet 71 of plastic magnet is integrally provided bymultiple molding on top of the main valve element 3. The multipolarmagnet 71 is in a ring-like shape coaxially with the main valve element3 and has a pair of the north portions and another pair of the southpole portions which are alternately arranged in a rotating direction.

A pressure chamber 41 is formed on an upper side (the other end surfaceside) of the main valve element 3 with use of the valve housing 1 andthe pilot valve 9 fit in the pilot valve guide-tube 39 formed on top ofthe valve housing 1. The pressure chamber 41 communicates with the highpressure connecting groove 37 and the high pressure port 19 through abypass clearance 43 (a valve outside-passage) between the pilot valve 9and the main valve element 3 and through a communicating clearance (notshown) between both end portions of a C-like piston ring 47 fit in apiston ring groove 45 of the main valve element 3, and is under pressureof the high pressure port 19.

The pilot valve guide-tube 39 is formed coaxially with thelarge-diameter cylindrical portion 2 and with the main valve elementguide-tube 6 of the valve housing 1, and a stem portion 10 of the pilotvalve 9 is axially movably fit in the pilot valve guide-tube 39 and in avalve holding hole 51 having a circular cross-section and formed in thecentral portion of the main valve element 3, and thus an end of a needlevalve portion 53 opens and/or closes a valve port 55 formed on the mainvalve element 3.

With this structure, the pilot valve 9 fits axially movably in both ofthe pilot valve guide-tube 39 on the side of the valve housing 1 and thevalve holding hole 51 on the side of the main valve element 3, therebysupported by both of the valve housing 1 and the main valve element 3.

Here, with respect to other specific shapes of the stem portion 10, forexample, as shown in FIGS. 8A to 8C, the ones having a D-shapedcross-section or a polygonal cross-section each having at least onecut-surface 12 on a peripheral surface, wherein only the remainingcircumferential surface 14 is put into contact with the pilot valveguide-tube 39 and with the valve holding hole 51, may be considered.

In these cases, a passage (not shown) connecting the pressure chamber 41with the valve port 55 is formed between the cut-surface 12 of the pilotvalve 9 and the valve holding hole 51.

Further, with respect to another specific shape of the stem portion 10,as shown in FIG. 8D, the one being in a substantially cylindrical shapecorresponding to an inner diameter of the pilot valve guide-tube 39 andof the valve holding hole 51, wherein whole the circumference of thecircumferential surface 14 is put into contact with the pilot valveguide-tube 39 and with the valve holding hole 51, may be considered.

In this case, as shown in FIG. 8E, a small diameter portion 10a isformed at an end portion, near the needle valve portion 53, of the stemportion 10, and a through passage 10b crossing the axis of the stemportion 10 in a radial direction is provided through the small diameterportion 10a, while a communicating passage 10c extending from an endsurface near the pilot valve guide-tube 39 located on the opposite sideof the needle valve portion 53 to the center of the through passage 10bis formed in the stem portion 10 in the axial direction. Thus, thethrough passage 10b and the communicating passage 10c, and clearancebetween the small diameter portion 10a and the valve holding hole 51constitutes a passage connecting the pressure chamber 41 with the valveport 55.

As shown in FIG. 1, the valve port 55 is located in the center of thebottom portion of the valve holding hole 51 and communicates with thepressure chamber 41 through the bypass clearance 43 on one hand and withthe low pressure connecting groove 35 through a communicating hole 57 onthe other hand.

The stem portion 10 of the pilot valve 9 is axially slidable in thecenter of the electromagnetic solenoid 11, and the pilot valve 9 isforced by a spring 61 provided between the pilot valve 9 and a fixedattractor 59 in a valve-closing direction. On the other hand, the pilotvalve 9 is attracted by the fixed attractor 59, which is arranged in thepilot valve guide-tube 39 facingly to an upper end surface of the stemportion 10, against spring force of the spring 61 by exciting anelectromagnetic coil 63 of the electromagnetic solenoid 11, and leavesthe valve port 55, thereby opening the pilot valve 9.

As shown in FIGS. 2 to 4, the electromagnetic coil 63 is fixed to thefixed attractor 59 being as a part of the valve housing 1 by means of amagnetic pole equipping electromagnetic coil attaching body 76. Themagnetic pole equipping electromagnetic coil attaching body 76 has anassembled body consisting of an outer box 65, being in a staple-likeshape and having a pair of main magnetic pole pieces 66 arranged with acircumferential difference by 180 degrees each other, and an under plate69 made of a metal sheet and having a pair of minor magnetic pole pieces70 assembled to the outer box 65 with a circumferential difference by180 degrees each other and also with a circumferential difference by 90degrees against the main magnetic pole pieces 66.

The outer box 65 is magnetically connected to one magnetic pole on theupper side of the electromagnetic coil 63, and the under plate 69 ismagnetically connected to the other magnetic pole on the lower side ofthe electromagnetic coil 63. As shown in FIGS. 1 and 4, the mainmagnetic pole pieces 66 and the minor magnetic pole pieces 70 are putinto contact with the peripheral surface of the large-diametercylindrical portion 2 of the valve housing 1 and rotate the main valveelement 3 by the magnetic action against the multipolar magnet 71. Withthis structure, the main magnetic pole pieces 66 face one magnetic polesof the multipolar magnet 71 through a peripheral wall of the valvehousing 1, and the minor magnetic pole pieces 70 face the other magneticpoles of the multipolar magnet 71 through the peripheral wall of thevalve housing 1.

As shown in FIG. 1, the magnetic pole equipping electromagnetic coilattaching body 76 is fixed with a bolt 67 to an upper end surface of thefixed attractor 59 through the outer box 65, and the under plate 69 ispositioned against the outer box 65 and fixed to it. With this, relativeposition between the main magnetic pole pieces 66 and the minor magneticpole pieces 70 is uniformly decided and this location-ship does notchange.

In the above-described electromagnetic actuator structure with theelectromagnetic solenoid 11 and the multipolar magnet 71, the mainmagnetic pole pieces 66 are magnetized to the north pole and the minormagnetic pole pieces 70 are magnetized to the south pole, and viceversa,according to direction of current in the electromagnetic coil 63 of theelectromagnetic solenoid 11, whereby the main valve element 3 rotatesfrom the first channel-switching position to the secondchannel-switching position, and viceversa, by the magnetic actionagainst the multipolar magnet 71.

In the 4-way valve 100 having the above-described structure, when anelectric current is sent to the electromagnetic coil 63 of theelectromagnetic solenoid 11 under a state shown in FIG. 1, the fixedattractor 59 is excited and the pilot valve 9 is attracted by the fixedattractor 59 and moved upward against spring force by the spring 61, andthen the valve port 55 opens.

Accordingly, the pressure chamber 41 communicates with the low pressureconnecting groove 35 and the low pressure port 15, and internal pressureof the pressure chamber 41 goes down from high pressure of the highpressure port 19 to low pressure of the low pressure port 15 sufferingsuction pressure of the compressor P. Consequently, the upper side ofthe main valve element 3 suffers lower pressure than the lower side ofthe main valve element 3, and the main valve element 3 rises by thispressure difference, separates from the valve-seat plate 5, and becomesin a state of being capable of rotating with low resistance.

Here, reason for the pressure drop of the pressure chamber 41 in a stateof the pilot valve 9 being open is that flow resistance between thepressure chamber 41 and the high pressure connecting groove 37communicating with the high pressure port 19 due to the communicatingclearance of the piston ring 47 is larger than flow resistance due tothe passage connecting the pressure chamber 41 with the low pressureconnecting groove 35 in the state of the pilot valve 9 being open.

In the state described above, the main valve element 3 rotates from thefirst channel-switching position shown in FIG. 5 to the secondchannel-switching position shown in FIG. 6 by the magnetic actionbetween the multipolar magnet 71 and all of the magnetized main magneticpole pieces 66 and the magnetized minor magnetic pole pieces 70, andviceversa, whereby the heat pump cycle is switched to the cooling modeor the heating mode.

After this, by stopping sending an electric current to theelectromagnetic coil 63, the pilot valve 9 drops by spring force by thespring 61 and closes, thereby shutting off the communication between thepressure chamber 41 and the low pressure connecting groove 35, and thenpressure of the high pressure connecting groove 37, i.e. of the highpressure port 19, is introduced into the pressure chamber 41 through thebypass clearance 43 and the communicating clearance of the piston ring47, whereby pressure in the pressure chamber 41 becomes the samepressure as in a space under the main valve element 3. Consequently, themain valve element 3 returns to the original dropped position by springforce by the spring 61 and by an own weight and comes into close contactwith the valve-seat plate 5.

During rotation of the main valve element 3, with the bottom surface 33of the main valve element 3 being apart from the valve-seat plate 5,from the first channel-switching position as shown in FIG. 5 toward thesecond channel-switching position as shown in FIG. 6 by sending anelectric current to the electromagnetic coil 63, a shift of relativeposition of the high pressure port 19 against the high pressureconnecting groove 37 from a state that the high pressure port 19 ispositioned between the bulkhead 38 and the first high pressure fluidjetting groove 44a to another state that the high pressure port 19 ispositioned between the bulkhead 38 and the second high pressure fluidjetting groove 44b brings the following.

When the high pressure port 19 is relatively positioned between thebulkhead 38 and the first high pressure fluid jetting groove 44a, asecond high pressure flow being separated from the high pressure fluidjetting from the high pressure port 19 to the high pressure connectinggroove 37 and being led to the bypass clearance 43 through the secondhigh pressure fluid jetting groove 44b is disturbed by the bulkhead 38,and a part of the disturbed flow of the high pressure fluid joins to afirst high pressure flow led to the bypass clearance 43 through thefirst high pressure fluid jetting groove 44a, whereby power of the firsthigh pressure flow wins that of the second high pressure flow. On thecontrary, when the high pressure port 19 is relatively positionedbetween the bulkhead 38 and the second high pressure fluid jettinggroove 44b, power of the second high pressure flow wins that of thefirst high pressure flow.

Accordingly, during rotation of the main valve element 3 from the firstchannel-switching position to the second channel-switching position,when position of the high pressure port 19 relative to the bulkhead 38has shifted from the first high pressure fluid jetting groove 44a sideto the second high pressure fluid jetting groove 44b side, rotatingforce in a direction from the first channel-switching position to thesecond channel-switching position (i.e. a counterclockwise sense in FIG.6) caused by power of the second high pressure flow being greater thanpower of the first high pressure flow is newly added to the main valveelement 3, thereby ensuring to rotate the main valve element 3 to thesecond channel-switching position without stopping.

On the contrary, during rotation of the main valve element 3 from thesecond channel-switching position toward the first channel-switchingposition by sending an electric current to the electromagnetic coil 63,a shift of relative position of the high pressure port 19 against thehigh pressure connecting groove 37 from a state that the high pressureport 19 is positioned between the bulkhead 38 and the second highpressure fluid jetting groove 44b to another state that the highpressure port 19 is positioned between the bulkhead 38 and the firsthigh pressure fluid jetting groove 44a brings the following.

When the high pressure port 19 is relatively positioned between thebulkhead 38 and the second high pressure fluid jetting groove 44b, thefirst high pressure flow being separated from the high pressure fluidjetting from the high pressure port 19 to the high pressure connectinggroove 37 and being led to the bypass clearance 43 through the firsthigh pressure fluid jetting groove 44a is disturbed by the bulkhead 38,and a part of the disturbed flow of the high pressure fluid joins to thesecond high pressure flow led to the bypass clearance 43 through thesecond high pressure fluid jetting groove 44b, whereby power of thesecond high pressure flow wins that of the first high pressure flow. Onthe contrary, when the high pressure port 19 is relatively positionedbetween the bulkhead 38 and the first high pressure fluid jetting groove44a, power of the first high pressure flow wins that of the second highpressure flow.

Accordingly, during rotation of the main valve element 3 from the secondchannel-switching position to the first channel-switching position, whenposition of the high pressure port 19 relative to the bulkhead 38 hasshifted from the second high pressure fluid jetting groove 44b side tothe first high pressure fluid jetting groove 44a side, rotating force ina direction from the second channel-switching position to the firstchannel-switching position (i.e. a clockwise sense in FIG. 5) caused bypower of the first high pressure flow being greater than power of thesecond high pressure flow is newly added to the main valve element 3,thereby ensuring to rotate the main valve element 3 to the firstchannel-switching position without stopping.

Here, during rotation of the main valve element 3 from the firstchannel-switching position to the second channel-switching position oroppositely from the second channel-switching position to the firstchannel-switching position, power of a third high pressure flow led fromthe high pressure connecting groove 37 to the bypass clearance 43through each of the first and second gates 40a,40b is smaller than thatof the first high pressure flow and of the second high pressure flow.Therefore, power of the third high pressure flow does not disturb theadditional rotating force to the main valve element 3 by power of thefirst high pressure flow or of the second high pressure flow.

As described above, during rotation of the main valve element 3 bysending an electric current to the electromagnetic coil 63 of theelectromagnetic solenoid 11, with the bottom surface 33 of the mainvalve element 3 being apart from the valve-seat plate 5, from one of thefirst and second channel-switching positions to the other of thepositions, rotating force of the main valve element 3 is increased bymeans of the additional rotating force arisen from difference in powerof the respective first and second high pressure flows led from the highpressure connecting groove 37 to the bypass clearance 43 through therespective first and second high pressure fluid jetting grooves 44a,44b,and thereby the main valve element 3 surely rotates. In other words,required driving force for rotating the main valve element 3 by means ofthe magnetic action to the multipolar magnet 71 due to the magnetismgenerated on the electromagnetic coil 63 is reduced.

Also, in a state that driving force for rotating the main valve element3 by means of the magnetic action to the multipolar magnet 71 due to themagnetism generated on the electromagnetic coil 63 does not work bystopping sending an electric current to the electromagnetic coil 63 ofthe electromagnetic solenoid 11, the main valve element 3 remains stableat the first channel-switching position or at the secondchannel-switching position by the above-mentioned additional rotatingforce arisen from difference in power of the respective first and secondhigh pressure flows.

Like the above, the bulkhead 38 acts as a stabilizer for keeping themain valve element 3 stable at the first channel-switching position orat the second channel-switching position in a state that an electriccurrent to the electromagnetic coil 63 of the electromagnetic solenoid11 is stopped.

And, the above-mentioned main valve element 3 with the first and secondgates 40a,40b and the first and second high pressure fluid jettinggrooves 44a,44b has a structural feature of even thickness beingadvantageous for the molding process, which enables improvement ofdimensional accuracy and manufacturing stability, thereby improving ayield rate and reducing a cost.

Further, pressure loss of the 4-way valve 100 can be reduced, or a flowcoefficient of the same can be increased by studying rotation propertyof the main valve element 3 and further studying shape of the main valveelement 3 for attaining better stability in channel-switching movementof the 4-way valve 100.

"specific structure of a second embodiment of a rotary channel-selectorvalve in accordance with the present invention"

Next, FIG. 9 shows a structure of a second embodiment of a 4-way valve,used as a channel-selector valve in a refrigerating cycle, in accordancewith the present invention.

For the 4-way valve shown in FIG. 9, the same reference numerals as inFIG. 1 are allotted to the same members or portions as in FIG. 1 showingthe first embodiment of a 4-way valve for a refrigerating cycle, anditerative descriptions are omitted hereinafter.

In the 4-way valve 100A of the second embodiment, since a needle valveportion 53 is separately formed from a stem portion 10 of a pilot valve9, the needle valve portion 53 can shift radially in the stem portion10.

As shown in FIG. 10, the needle valve portion 53 has a head 54 movablyaccommodated in a needle valve supporting hole 10d formed at an endportion of the stem portion 10 and is allowed to move radially andaxially within a predetermined range by a fixed ring 56 fixed the end ofthe stem portion 10.

The head 54 has a spherical head surface 54a to abut on a bottom surface(a ceiling surface) 10e of the needle valve supporting hole 10d. Withthis mechanism, the needle valve portion 53 can tilt by about 2 degreesagainst the stem portion 10.

And, as shown in FIG. 9, a pilot valve guide-tube 39 is provided with achamber (i.e. a spring chamber) 62 between the stem portion 10a and afixed attractor 59.

A bleeding passage 9a to open the chamber 62 to a pressure chamber 41 isformed in the stem portion 10, and a passage connecting the pressurechamber 41 with a valve port 55 is formed with the chamber 62, thebleeding passage 9a, and a clearance between the stem portion 10 and avalve holding hole 51.

In the 4-way valve 100A of the second embodiment, constructed as above,since the needle valve portion 53 is separately formed from the stemportion 10 of the pilot valve 9 so as to enable the needle valve portion53 to shift radially in the stem portion 10, the needle valve portion 53radially self-aligningly shifts relatively to the valve port 55 during aprocess of closing the valve port 55 with the needle valve portion 53,that is, radial position of the needle valve portion 53 relative to thevalve port 55 can be automatically corrected during the process.

Further, since the spherical head surface 54a of the needle valveportion 53 abuts on the bottom surface 10e of the needle valvesupporting hole 10d, the needle valve portion 53 can tiltself-aligningly against the stem portion 10 and directional position ofthe needle valve portion 53 relative to the stem portion 10 can becorrected automatically.

With the above structure or mechanism, even if a supporting condition ofthe stem portion 10 by the valve port 55, a concentricity between thestem portion 10 and the needle valve portion 53, a concentric machiningaccuracy between the valve holding hole 51 and the valve port 55, apositioning accuracy of the pilot valve guide-tube 39, or an assemblingaccuracy of the main valve element 3 to the valve housing 1 is not sogood, radial position or directional position of the needle valveportion 53 relative to the valve port 55 can be corrected, therebyensuring to shut off the valve port 55 with the needle valve portion 53.

Further, since the chamber 62 formed with the pilot valve guide-tube 39,the stem portion 10, and the fixed attractor 59 opens to the pressurechamber 41 through the bleeding passage 9a, even if fluid like alubricant or a refrigerant invades the chamber 62, the fluid flows tothe pressure chamber 41 through the bleeding passage 9a without stayingin the chamber 62, thereby assuring smooth opening and closing movementof the pilot valve 9 for a long period.

Still further, since the needle valve portion 53 and the stem portion 10are connected movably in the axial direction of the main valve element3, a shock of a hit by the needle valve portion 53 against the valveport 55 at the time of closing the pilot valve 9 can be lightened withaxial movement of the needle valve portion 53 relative to the stemportion 10, thereby improving durability of the needle valve portion 53and the valve port 55 against wear or chipping or the like.

FIGS. 11 to 14 show modified embodiments of the pilot valve 9 assembledto the rotary channel-selector valve in accordance with the presentinvention. In FIGS. 11 to 14, the same reference numerals as in FIG. 10are allotted to the same members or portions as in FIG. 10, anditerative descriptions are omitted.

In a modified embodiment shown in FIG. 11, a high-slippery resin plate58 of fluororesin with high elasticity is arranged on the bottom portionof the needle valve supporting hole 10d, and therefore the sphericalhead surface 54a of the needle valve portion 53 abuts on the stemportion 10 through the high-slippery resin plate 58.

With this structure, the needle valve portion 53 can surely tiltself-aligningly relatively to the stem portion 10 with low resistance.

In a modified embodiment shown in FIG. 12, a compression coil spring 60with a predetermined load is assembled between the needle valve portion53 and the stem portion 10.

In this modified embodiment, since the needle valve portion 53 is pushedby spring force by the compression coil spring 60, the needle valveportion 53 does not get rickety against the stem portion 10 in avalve-opened state and further, valve closing-pressure can be controlledwith the compression coil spring 60.

Still further, since the compression coil spring 60 is provided betweenthe needle valve portion 53 and the stem portion 10, a shock of a hit bythe needle valve portion 53 against the valve port 55 at the time ofclosing the pilot valve 9 can be absorbed by the compression coil spring60, thereby further improving durability of the needle valve portion 53and the valve port 55 against wear or chipping or the like.

In a modified embodiment shown in FIG. 13, a valve retainer 64 with aspherical portion 64a is provided, and the spherical portion 64a ispushed to the needle valve portion 53 by spring force by the compressioncoil spring 60.

With this structure, the needle valve portion 53 does not get ricketyagainst the stem portion 10 in a valve-opened state, and valveclosing-pressure can be controlled with the compression coil spring 60,and further, since the spherical portion 64a is pushed to the needlevalve portion 53, the needle valve portion 53 can tilts self-aligninglyagainst the stem portion 10 at the time of valve-closing and directionalposition of the needle valve portion 53 relative to the stem portion 10can be corrected automatically.

In a modified embodiment shown in FIGS. 14A and 14B, a cross-shaped leafspring 64A, instead of the compression coil spring 60, with a sphericalportion 64b in the central portion thereof is provided between theneedle valve portion 53 and the stem portion 10 in a state of having apredetermined load. The leaf spring 64A abuts on the needle valveportion 53 by means of the spherical portion 64b.

With this structure, the needle valve portion 53 does not get ricketyagainst the stem portion 10 in a valve-opened state, and valveclosing-pressure can be controlled with the leaf spring 64A, andfurther, since the needle valve portion 53 is pushed by the sphericalportion 64b, the needle valve portion 53 can tilts self-aligninglyagainst the stem portion 10 at the time of valve-closing and directionalposition of the needle valve portion 53 relative to the stem portion 10can be corrected automatically.

"specific structure of a third embodiment of a rotary channel-selectorvalve in accordance with the present invention"

Next, FIG. 15 shows a structure of a third embodiment of a 4-way valve,used as a channel-selector valve in a refrigerating cycle, in accordancewith the present invention.

For the 4-way valve shown in FIG. 15, the same reference numerals as inFIG. 1 are allotted to the same members or portions as in FIG. 1 showingthe first embodiment of a 4-way valve for a refrigerating cycle, anditerative descriptions are omitted hereinafter.

And, in the 4-way valve 100B of the third embodiment, a multipolarmagnet 71 of plastic magnet is integrally provided by insert molding ontop of the main valve element 3. As shown in FIG. 25, the multipolarmagnet 71 is in a ring-like shape coaxially with the main valve element3 and has a pair of the north portions 72 and another pair of the southpole portions 74 which are alternately arranged in a rotating direction.

As shown in FIG. 15, an electromagnetic coil 63 is fixed to a fixedattractor 59 being as a part of a valve housing 1 by means of a magneticpole equipping electromagnetic coil attaching body 76. As shown in FIGS.16,18, and 24, the magnetic pole equipping electromagnetic coilattaching body 76 has an assembled body consisting of an outer box 65,being in a staple-like shape and having a pair of main magnetic polepieces 66 arranged with a circumferential difference by 180 degrees eachother, and an under plate 69 made of a metal sheet and having a pair ofminor magnetic pole pieces 70 assembled to the outer box 65 with acircumferential difference by 180 degrees each other and also with acircumferential difference by 90 degrees against the main magnetic polepieces 66.

And, as shown in FIG. 16, a convex 75, in a concave-like shape whenlooked at from an outer surface side of the outer box 65, is formed onthe back surface of the outer box 65 at each comer thereof. These four(4) convexes 75 engage a periphery of one end surface of a coil bobbin63a being in a shape of a substantially oval and simultaneously aperiphery 65e of the outer box 65 abuts on a side end 63c of a thickportion 63b projecting from the coil bobbin 63a at an end surfacethereof for reinforcing roots of lead wires 64 drawn out of the coilbobbin 63a so as to position the electromagnetic coil 63 with respect tothe outer box 65 in a rotating direction of the main valve element 3.

The outer box 65 is magnetically connected to one magnetic pole on theupper side of the electromagnetic coil 63, and an under plate 69 ismagnetically connected to the other magnetic pole on the lower side ofthe electromagnetic coil 63. As shown in FIGS. 18 and 23, the mainmagnetic pole pieces 66 and the minor magnetic pole pieces 70 are putinto contact with the peripheral surface of a large-diameter cylindricalportion 2 of the valve housing 1 and rotate the main valve element 3 bythe magnetic action against the multipolar magnet 71. With thisstructure, the main magnetic pole pieces 66 face one magnetic poles ofthe multipolar magnet 71 through a peripheral wall of the valve housing1, and the minor magnetic pole pieces 70 face the other magnetic polesof the multipolar magnet 71 through the peripheral wall of the valvehousing 1.

As shown in FIG. 15, the magnetic pole equipping electromagnetic coilattaching body 76 is fixed with a bolt 67 to an upper end surface of thefixed attractor 59 through the outer box 65. The under plate 69 hasconnecting bridge-pieces 69a 69b extending with a circumferentialdifference by 90 degrees against the minor magnetic pole pieces 70 and,as shown in FIGS. 18 and 19, end portions of the respective connectingbridge-pieces 69a 69b engage respective small openings 65a 65b formed onthe outer box 65, thereby positioning the under plate 69 with respect tothe outer box 65. With this, relative position between the main magneticpole pieces 66 and the minor magnetic pole pieces 70 is uniformlydecided and this location-ship does not change.

A buffering sheet 63A made of an elastic material such as rubber isprovided between the other end surface of the coil bobbin 63a and theconnecting bridge-pieces 69a 69b of the under plate 69, and thebuffering sheet 63A prevents transmission of vibration of theelectromagnetic coil 63 to the under plate 69 and to the valve housing1, which vibration of the electromagnetic coil 63 is arisen by a bump,against the fixed attractor 59, of the pilot valve 9 attracted by thefixed attractor 59 by sensing an electric current to the electromagneticcoil 63.

In the above-described electromagnetic actuator structure with anelectromagnetic solenoid 11 and the multipolar magnet 71, the mainmagnetic pole pieces 66 are magnetized to the north pole and the minormagnetic pole pieces 70 are magnetized to the south pole, and viceversa,according to direction of current in the electromagnetic coil 63 of theelectromagnetic solenoid 11.

In the 4-way valve 100B having the above-described structure, when anelectric current is sent to the electromagnetic coil 63 of theelectromagnetic solenoid 11 under a state shown in FIG. 15, the fixedattractor 59 is excited and the pilot valve 9 is attracted by the fixedattractor 59 and moved upward against spring force by a spring 61, andthen a valve port 55 opens.

Accordingly, a pressure chamber 41 communicates with a low pressureconnecting groove 35 and a low pressure port 15, and internal pressureof the pressure chamber 41 goes down from high pressure of a highpressure port 19 to low pressure of the low pressure port 15.Consequently, the upper side of the main valve element 3 suffers lowerpressure than the lower side of the main valve element 3, and the mainvalve element 3 rises by this pressure difference, separates from avalve-seat plate 5, and becomes in a state of being capable of rotatingwith low resistance.

In the state described above, by the magnetic repulsion between the mainmagnetic pole pieces 66 magnetized to the north pole by sending anelectric current to the electromagnetic coil 63 and the north portions72 of the multipolar magnet 71 and also by the magnetic repulsionbetween the minor magnetic pole pieces 70 magnetized to the south poleby sending an electric current to the electromagnetic coil 63 and thesouth portions 74 of the multipolar magnet 71, the main valve element 3rotates in a counterclockwise sense in FIGS. 5 and 6 and shifts from thefirst channel-switching position shown (shown in FIGS. 5 and 25A) to thesecond channel-switching position (shown in FIGS. 6 and 25B).

Consequently, the south pole portions 74 of the multipolar magnet 71 areattracted, with a face to face arrangement, to the main magnetic polepieces 66 magnetized to the north pole and the north pole portions 72 ofthe multipolar magnet 71 are attracted, with a face to face arrangement,to the minor magnetic pole pieces 70 magnetized to the south pole,thereby holding the main valve element 3 at the second channel-switchingposition and the heat pump cycle is switched from the cooling mode tothe heating mode.

By stopping sending an electric current to the electromagnetic coil 63,the pair of the main magnetic pole pieces 66 merely as metal with nomagnetic pole are attracted by the south pole portions 74 of themultipolar magnet 71 and the minor magnetic pole pieces 70 merely asmetal with no magnetic pole are attracted by the north pole portions 72of the multipolar magnet 71, and the main valve element 3 is held at thesecond channel-switching position.

Along with stopping sending an electric current to the electromagneticcoil 63, the pilot valve 9 drops by spring force by the spring 61 andcloses, thereby shutting off the communication between the pressurechamber 41 and the low pressure connecting groove 35, and then pressureof a high pressure connecting groove 37, i.e. of the high pressure port19, is introduced into the pressure chamber 41 through a bypassclearance 43 and a communicating clearance of a piston ring 47, wherebypressure in the pressure chamber 41 becomes the same pressure as in aspace under the main valve element 3. Consequently, the main valveelement 3 returns to the original dropped position by spring force bythe spring 61 and by an own weight and comes into close contact with thevalve-seat plate 5 and is kept stable at the second channel-switchingposition (i.e. position of channel-switching completion), with highreliability of movement.

In case that the heat pump cycle is switched from the heating mode tothe cooling mode, direction of an electric current to theelectromagnetic solenoid 11 is reversed, and the main valve element 3 israised upward by opening the pilot valve 9, and simultaneously the mainmagnetic pole pieces 66 and the minor magnetic pole pieces 70 aremagnetized to the south pole and to the north pole, respectively.

In the state described above, by the magnetic repulsion between the mainmagnetic pole pieces 66 magnetized to the south pole by sending anelectric current to the electromagnetic coil 63 and the south portions74 of the multipolar magnet 71 and also by the magnetic repulsionbetween the minor magnetic pole pieces 70 magnetized to the north poleby sending an electric current to the electromagnetic coil 63 and thenorth portions 72 of the multipolar magnet 71, the main valve element 3rotates in a clockwise sense in FIGS. 5 and 6 and shifts from the secondchannel-switching position shown (shown in FIGS. 6 and 25B) to the firstchannel-switching position (shown in FIGS. 5 and 25A).

Consequently, the south pole portions 74 of the multipolar magnet 71 areattracted, with a face to face arrangement, to the main magnetic polepieces 66 magnetized to the north pole and the north pole portions 72 ofthe multipolar magnet 71 are attracted, with a face to face arrangement,to the minor magnetic pole pieces 70 magnetized to the south pole,thereby holding the main valve element 3 at the first channel-switchingposition and the heat pump cycle is switched from the heating mode tothe cooling mode.

By stopping sending an electric current to the electromagnetic coil 63,the pair of the main magnetic pole pieces 66 merely as metal with nomagnetic pole are attracted by the south pole portions 72 of themultipolar magnet 71 and the minor magnetic pole pieces 70 merely asmetal with no magnetic pole are attracted by the north pole portions 74of the multipolar magnet 71, and the main valve element 3 is held at thefirst channel-switching position.

Along with stopping sending an electric current to the electromagneticcoil 63, the pilot valve 9 drops by spring force by the spring 61 andcloses, thereby shutting off the communication between the pressurechamber 41 and the low pressure connecting groove 35, and then pressureof the high pressure connecting groove 37, i.e. of the high pressureport 19, is introduced into the pressure chamber 41 through the bypassclearance 43 and the communicating clearance of a piston ring 47,whereby pressure in the pressure chamber 41 becomes the same pressure asin a space under the main valve element 3. Consequently, the main valveelement 3 returns to the original dropped position by spring force bythe spring 61 and by an own weight and comes into close contact with thevalve-seat plate 5 and is kept stable at the first channel-switchingposition (i.e. position of channel-switching completion), with highreliability of movement.

As shown in FIG. 18, the 4-way valve 100B of the third embodiment isprovided with a downwardly bent whirl-stopping piece 69c on an underplate 69. As shown in FIG. 20, a flat surface 6a is partially formed bypressing on the peripheral surface of a main valve element guide-tube 6of the valve housing 1, and as shown in FIG. 18 the magnetic poleequipping electromagnetic coil attaching body 76 is circumferentiallypositioned on the valve housing 1 by a surface-engagement between theflat surface 6a and the whirl-stopping piece 69c.

Accordingly, the main magnetic pole pieces 66 and the minor magneticpole pieces 70 are positioned at the circumferential positions requiredfor rotating the main valve element 3 between the predeterminedchannel-switching positions.

"specific structure of a fourth embodiment of a rotary channel-selectorvalve in accordance with the present invention"

Next, FIGS. 26 to 31 show a structure of a fourth embodiment of a 4-wayvalve, used as a channel-selector valve in a refrigerating cycle, inaccordance with the present invention.

For the 4-way valve shown in FIGS. 26 to 31, the same reference numeralsas in FIGS. 15 to 25 are allotted to the same members or portions as inFIGS. 15 to 25 showing the third embodiment of a 4-way valve for arefrigerating cycle, and iterative descriptions are omitted hereinafter.

And, in the 4-way valve 100C of the fourth embodiment, as shown in FIGS.28 to 30, a mounting engagement portion 59b with flat side-surfaces 59ais formed by two-plane machining at an upper end portion of a fixedattractor 59.

As shown in FIGS. 26 and 27, a concave 65c is formed by louver-pressingwork on a top surface of an outer box 65 of a magnetic pole equippingelectromagnetic coil attaching body 76. The concave 65c is in arectangular shape as shown in FIG. 27 and has parallel edges 65d formedby two-plane machining and exactly engaging the flat side-surfaces 59aas shown in FIG. 28.

With an engagement between the concave 65c and the mounting engagementportion 59b in an exactly engaged state of the parallel edges 65d of theconcave 65c of the outer box 65 with the flat side-surfaces 59a, amagnetic pole equipping electromagnetic coil attaching body 76 iscircumferentially positioned on a valve housing 1.

Accordingly, a main magnetic pole pieces 66 and a minor magnetic polepieces 70 are positioned at the circumferential positions required forrotating a main valve element 3 between predetermined channel-switchingpositions.

"specific structure of a fifth embodiment of a rotary channel-selectorvalve in accordance with the present invention"

Next, FIGS. 32 to 34 show a structure of a fifth embodiment of a 4-wayvalve, used as a channel-selector valve in a refrigerating cycle, inaccordance with the present invention.

For the 4-way valve shown in FIGS. 32 to 34, the same reference numeralsas in FIGS. 26 to 31 are allotted to the same members or portions as inFIGS. 26 to 31 showing the fourth embodiment of a 4-way valve for arefrigerating cycle, and iterative descriptions are omitted hereinafter.

And, though the mounting engagement portion 59b with flat side-surfaces59a is directly formed two-plane machining at the upper end portion ofthe fixed attractor 59 in the above-described fourth embodiment, anothermounting engagement portion 59b is formed by fixing a positioning plate81 with flat side-surfaces 80 on the top end of a fixed attractor 59 bymeans of welding or the like in the 4-way valve 100D of the fifthembodiment shown in FIGS. 32 to 34.

In this case, the mounting engagement portion 59b may be in a shape of apolygon such as a square or a pentagon, without being limited to thetwo-plane machining shape.

Further, though embodiments and the modified embodiments of a 4-wayvalve are described hereinbefore, the present invention is alsoapplicable to a rotary 3-way valve and further applicable to a rotarychannel-selector valve wherein a main valve element rotates with keepingin contact with a valve-seat plate, besides the rotary channel-selectorvalve with the pilot valve wherein the main valve element 3 becomesapart from the valve-seat plate 5 during rotation as in theabove-mentioned embodiments.

What is claimed is:
 1. A rotary channel-selector valve, comprising:avalve housing; a main valve element accommodated in the valve housing,being capable of rotating between a first channel-switching position anda second channel-switching position, and having high and low pressureconnecting grooves isolated from each other on one end surface thereof;a valve-seat plate, fixed to the valve housing, facing the one endsurface of the main valve element, and having high and low pressureports and first and second switching ports, wherein a connecting pointof the high pressure port shifts from one of the first and secondswitching ports to the other thereof through the high pressureconnecting groove by rotating the main valve element between the firstand second channel-switching positions and simultaneously a connectingpoint of the low pressure port shifts from the other of the first andsecond switching ports to the one thereof through the low pressureconnecting groove, and rotation of the main valve element between thefirst and second channel-switching positions is performed with the oneend surface of the main valve element being apart from the valve-seatplate; a first high pressure fluid jetting groove formed on the one endsurface of the main valve element, wherein one end portion, of the highpressure connecting groove, positioned near the high pressure port atthe first channel-switching position opens to a periphery of the mainvalve element through the first high pressure fluid jetting groove; asecond high pressure fluid jetting groove formed on the one end surfaceof the main valve element and being isolated from the first highpressure fluid jetting groove, wherein another end portion, of the highpressure connecting groove, positioned near the high pressure port atthe second channel-switching position opens to the periphery of the mainvalve element through the second high pressure fluid jetting groove; anda bulkhead being in a shape of a projecting strip and provided on abottom surface of the high pressure connecting groove, wherein sincehigh pressure fluid jetting from the high pressure port to the highpressure connecting groove flows easier toward the first high pressurefluid jetting groove than toward the second high pressure fluid jettinggroove by an action of the bulkhead in a state that the high pressureport positions nearer one end portion of the high pressure connectinggroove than the bulkhead, power of a first high pressure flow jettingfrom the first high pressure fluid jetting groove to the periphery ofthe main valve element wins power of a second high pressure flow jettingfrom the second high pressure fluid jetting groove to the periphery ofthe main valve element and rotating force in a direction from the secondchannel-switching position to the first channel-switching position actson the main valve element due to difference of power between the firsthigh pressure flow and the second high pressure flow, and, on thecontrary, since high pressure fluid jetting from the high pressure portto the high pressure connecting groove flows easier toward the secondhigh pressure fluid jetting groove than toward the first high pressurefluid jetting groove by an action of the bulkhead in a state that thehigh pressure port positions nearer another end portion of the highpressure connecting groove than the bulkhead, power of a second highpressure flow jetting from the second high pressure fluid jetting grooveto the periphery of the main valve element wins power of a first highpressure flow jetting from the first high pressure fluid jetting grooveto the periphery of the main valve element and rotating force in adirection from the first channel-switching position to the secondchannel-switching position acts on the main valve element due todifference of power between the first high pressure flow and the secondhigh pressure flow.
 2. The rotary channel-selector valve as claimed inclaim 1, further comprising:a valve outside-passage formed between aninner surface of the valve housing and the periphery of the main valveelement and communicating with the high pressure port; a pressurechamber formed between another end surface of the main valve element andthe valve housing and communicating with the valve outside-passage; agate portion formed on one end surface of the main valve element andopening the high pressure connecting groove to the periphery of the mainvalve element; a pilot passage formed in the main valve element andconnecting the low pressure connecting groove to the pressure chamber,permitting larger flow than that of the valve outside-passage; and apilot valve provided in the valve housing, wherein the main valveelement is pushed to the valve-seat plate by the high pressure fluidflowing into the pressure chamber through the gate portion and the valveoutside-passage after jetting from the high pressure port to the highpressure connecting groove by closing the pilot passage provided in thevalve housing by the pilot valve and, on the contrary, the main valveelement separates from the valve-seat plate by disappearance of forcepushing the main valve element toward the valve-seat plate by drop ofpressure in the pressure chamber by opening the pilot passage by thepilot valve, and the first high pressure fluid jetting groove and thesecond high pressure fluid jetting groove each have a largercross-section than that of the gate portion and, therefore, power of thefirst high pressure flow wins that of a third high pressure flow jettingfrom the high pressure connecting groove to the periphery of the mainvalve element through the gate portion in a state that the high pressureport positions nearer one end portion of the high pressure connectinggroove than the bulkhead and, on the contrary, power of the second highpressure flow wins that of the third high pressure flow jetting from thehigh pressure connecting groove to the periphery of the main valveelement through the gate portion in a state that the high pressure portpositions nearer another end portion of the high pressure connectinggroove than the bulkhead.